I will quickly run through what you need to do to add a template. The first thing to do is work out what you would like as a template and customise it to fit your project. The file that the templates html snippets are stored in is located in the default.js file found here:
/plugins/editors/jckeditor/plugins/templates/templates/default.js
You can create and define your templates by simply adding your custom HTML code to the default.js file as detailed below.
{title: 'Image and Title', image: 'template1.gif', description: 'Description.', html: <p>Text here</p>'}
Remember that JavaScript can’t have any new line character so your HTML will have to be on one line. Then take a screenshot of your HTML template, crop it down to 100 x 70 pixels and upload the icon to the directory located here:
/plugins/editors/jckeditor/plugins/templates/templates/images/